<para>These functions and macros convert back and forth from C character types to Lisp. The macros <function>ECL_CHAR_CODE</function> and <function>ECL_CODE_CHAR</function> perform this coercion without checking the arguments. The functions <function>ecl_char_code</function> and <function>ecl_base_char_code</function>, on the other hand, verify that the argument has the right type and signal an error otherwise.</para>

<para>These functions check or change the case of a character. Note that in an Unicode context, the output of these functions might not be accurate (for instance when the uppercase character has two or more codepoints).</para>